The major objectives will be to: (1) compare data obtaned in a school setting utilizing a self-administered screening tool (the Center for Epidemiologic Studies Depression Scale), with information obtained and diagnoses made via structured diagnostic interviews at an established clinical research unit; (2) study the frequency, distribution and stability of depressive symptoms, major depressive disorder (MDD) and suicidal ideation in early adolescents; and (3) explore the possible relationships between the above dimensions and perceived family environment and life changes, also in early adolescents. A longitudinal study design will be employed, with data collection occurring annually for three years. The sample (N=3200) will consist of seventh and eighth graders enrolled in four public middle schools. In years 2 and 3, students will be followed as they progress into the ninth and tenth grades. Additionally the new classes of seventh graders will be added to the sample. Each subject will be assigned and identification number (known only to school officials) so that successive responses can be linked. Students will be approached in a group fashion during a class. Data will be collected via self-administered written questionnaires. The questionnaires will include: (1) a demographic and general information section; (2) The Center for Epidemiologic Studies Depression Scale; (3) The Family Cohesion and Evaluation Scales; and (4) The Life Events Schedule for Adolescents. School records will be used to provide additional data and to validate a portion of the student's responses. These records will be reviewed for information on: (1) grade point average; (2) absenteeism; (3) disciplinary problems at school; and (4) diagnoses of learning and/or emotional problems. All students obtaining high scores on the depression scale (indicating probable cases) and a random sample of students receiving low scores will be referred to Barbara Geller, M.D., at the Hall Psychiatric Institute, for clinical evaluation. The clinical evaluation will consist of a structured interview (utilizing the Schedule for Affective Disorders and Schizophrenia in School Age Children and the Children's Depression Rating Scale) of the adolescent and his parent(s). Diagnosis will be made utilizing DSM-III criteria. Adolescents diagnosed as depressed will be offered treatment.